Affordable Open Hardware Arduino-based Technology for Blind People

In this article I would like to tell you about an ultrasonic keychain the device for the blind which help detecting obstacles at a higher level at which a simple white cane cannot warn the users about. These obstacles may be high-sided cars, gate crossings, high fences etc.

The keychain can be placed around the neck or in the hand and can be used as a flash light. The algorithm of work of these devices is based on a reflection of ultrasonic waves from an obstacle. The distance to an obstacle is measured by calculating the time difference between the moment of generation of the impulse and the moment of receiving the reflected echo signal. Our developed devices have the following specifications: